The present invention deals with a wiping device of windows of motor vehicles with a wiper arm guided on the motor vehicle and oscillatingly driven in known wiping devices (German Patent Disclosure DE 32 20 274 A1), a considerable centrifugal force acts on the hinge connection between the wiper arm and the wiper blade during the oscillating working motion; particularly in so- called single-lever wiper systemsxe2x80x94because of the comparatively large and thus heavy wiper bladexe2x80x94this force is further increased. This centrifugal force must be intercepted by a pin that forms the hinge axis and by a hairpin-like curvature, forming the pin bearing, of the free end of the wiper arm or a retention spring adapted to this curvature. Since furthermore the hinge connection is still exposed to environmental factors, such as road dirt, it can become deflected, because of the linear support of the pin in the curvature, which then impairs the wiping results, because in this hinge the requisite adaptation of the wiper blade to the course of the spherically curved surface of the window is done during the wiping operation.
It is therefore an object of the present invention to provide a wiping device which avoids the disadvantages of the prior art.
In keeping with these objects, one feature of present invention resides, briefly stated, in the wiping device in which at least one support shoulder is fixed to the wiper arm and pointed toward the oscillation axis, to cooperate with a check shoulder fixed on the wiper blade and pointing away from the oscillation axis.
In the wiper blade of the invention with the hinge between the wiper arm and the wiper blade is completely relieved during wiping operation, since given careful adaptation of the check shoulder to the support shoulder, no centrifugal forces can act on the hinge. Since the support is effected on generally flat shoulders, the shoulders are subject to practically no wear.
For technical production reasons, it is advantageous to dispose the support shoulder fixed to the wiper arm on the coupling part of the wiper arm, and the check shoulder of the wiper blade on the coupling part of the wiper blade, the coupling parts being part of the connection device.
A wiping device of compact structure is obtained if the support shoulder and the check shoulder are disposed between the oscillation axis and the hinge axis.
An especially simple disposition of the support shoulders and check shoulders can be accomplished if, in a feature of the invention, the coupling part of the wiper arm has a wall located in a plane vertical to the window and extending substantially in the direction of the longitudinal axis of the wiper arm, adjacent to which wall is a surface of the coupling part of the wiper blade, and if furthermore the support shoulder is embodied on this wall and the check shoulder is embodied on this surface.
In a connection device of very low design, the invention can be realized if the coupling part of the wiper arm, crosswise to the longitudinal axis of the wiper arm, has a U-shaped cross section; if furthermore one bearing receptacle each for a pivot pin of the coupling part of the wiper blade is disposed in each of the legs of the U of this coupling part, which receptacle dips between the legs of the U of the coupling part of the wiper arm, and if finally the inside of at least one leg of the U forms the wall that is provided with the support shoulder.
Expediently, the coupling part of the wiper blade has an at least imaginary base body, in which the pivot pin is integrated in such a way that its two ends protrude from it, and furthermore at least one face of the base body forms the surface that is provided with the check shoulder.
If both the support shoulder and the check shoulder have a curved course about the axis of the hinge, and the respective radius of curvature corresponds to the respective spacing from the hinge axis, then a comparatively large-area contact of the two shoulders on one another is obtained, which minimizes their wear.
Wear of the shoulders can be further minimized if, in an extension of the concept of the invention, the support shoulder is embodied on a rib-like protrusion on the inside of one leg of the U, and the check shoulder is embodied on the side wall of a groove in the surface, toward this leg of the U, of the base body.
In this way, the shoulders are located inside the connection device and are thus largely protected against dirt from the road.
In certain applications, it can be advantageous if a plurality of support shoulders and check shoulders are embodied on each of the two coupling parts.
Technical advantages in terms of production are obtained if the two coupling parts are made from a plastic.
Further advantageous refinements and features of the invention are disclosed in the ensuing description of two exemplary embodiments shown in the associated drawing.